'Bushmaster', prototype B3, four wheel drive Infantry Mobility Vehicle (IMV). The vehicle has a box shaped, welded steel hull with horizontal roof, vertical side, rear and front plates. The bonnet slopes gradually up to the three wipers and large one piece armoured windscreen. The crew side windows are also armoured and have firing ports fitted. There are two large storage bins with hinged doors mounted on each side of the vehicle and two smaller ones outboard of the larger ones. Attached to the port side exterior of the vehicle, between the main storage bins, is a 10 tonne, hydraulic winch with guide rollers for the cable, mounted inline with the winch at the front and rear of the vehicle. The exhaust pipe runs along the starboard side of the vehicle.

There are four hinged roof hatches above the passenger compartment and a fifth circular hatch located above the crew compartment, with a fitted mount to support a machine gun, ammunition boxes and spotlight. Two spare tyres with canvas camouflage covers are mounted high at the rear on either side of the vehicle. Also at the rear of the vehicle, below the spare tyres are three steel boxes (2 port & 1 starboard) containing wet cell batteries. Crew and passenger access is through the rear door via fold down steps. The interior of the vehicle has provision for carrying seven seated passengers and two seated crew members.

The passenger compartment is fitted with three seats on the port side and four seats on the starboard side. All seven passenger seats face towards the centre of the vehicle and have harness seat belts fitted. There are three armoured windows fitted to each side of the passenger compartment and another in the rear door. Some of these windows have firing ports. Standard equipment for the vehicle includes power steering, automatic transmission, air conditioning and a cooled fresh water supply system. The vehicle is painted in the standard Australian Army three colour scheme of tan, olive drab and black.

This prototype vehicle, designated B3 along with prototype B1, was deployed to East Timor during INTERFET in 1999-2000 and was used for senior officer and VIP protected transport. Passengers included Mr Robert Hill, General Peter Cosgrove and Mr Xunana Gusmao.